Germline mutations in the extracellular domains of the 55 kDa TNF receptor, TNFR1, define a family of dominantly inherited autoinflammatory syndromes

Autosomal dominant periodic fever syndromes are characterized by unexplained episodes of fever and severe localized inflammation. In seven affected families, we found six different missense mutations of the 55 kDa tumor necrosis factor receptor (TNFR1), five of which disrupt conserved extracellular disulfide bonds. Soluble plasma TNFR1 levels in patients were approximately half normal. Leukocytes bearing a C52F mutation showed increased membrane TNFR1 and reduced receptor cleavage following stimulation. We propose that the autoinflammatory phenotype results from impaired downregulation of membrane TNFR1 and diminished shedding of potentially antagonistic soluble receptor. TNFR1-associated periodic syndromes (TRAPS) establish an important class of mutations in TNF receptors. Detailed analysis of one such mutation suggests impaired cytokine receptor clearance as a novel mechanism of disease.

Endoscopic ultrasound guided fine needle aspiration biopsy: a large single centre experience

BACKGROUND

Endoscopic ultrasound guided fine needle aspiration biopsy (EUS-FNA) is a recent innovation in the evaluation of gastrointestinal and pulmonary malignancies.

AIMS

To review the experience with EUS-FNA of a large single centre.

METHODS

333 consecutive patients underwent EUS-FNA. Follow up data were available on 327 lesions in 317 patients, including 160 lymph nodes, 144 pancreatic lesions, 15 extraintestinal masses, and eight intramural tumours.

RESULTS

A primary diagnosis of malignancy was obtained by EUS-FNA in 62% of patients with clinically suspicious lesions. The overall accuracy of EUS-FNA for the diagnosis of malignancy was 86%, with sensitivity of 84% and specificity of 96%. With respect to lesion types, the sensitivity, specificity, and accuracy were 85%, 100%, and 89% for lymph nodes; 82%, 100%, and 85% for pancreatic lesions; 88%, 100%, and 90% for perirectal masses; and 50%, 25%, and 38% for intramural lesions, respectively. Compared with size and sonographic criteria, EUS-FNA in the evaluation of lymph nodes provided superior accuracy and specificity, without compromising sensitivity. Inadequate specimens were obtained from only six patients, including 3/5 with stromal tumors. Only one complication occurred.

CONCLUSIONS

EUS-FNA is safe and can readily obtain tissue specimens adequate for cytopathological diagnoses. Compared with size and sonographic criteria, it is a superior modality for the detection of nodal metastases. While providing accurate diagnosis of pancreatic and perirectal malignancies, results suggest the technique is less useful for intramural lesions.

Plasticity in the organization and sequences of human KIR/ILT gene families

The approximately 1-Mb leukocyte receptor complex at 19q13.4 is a key polymorphic immunoregion containing all of the natural killer-receptor KIR and related ILT genes. When the organization of the leukocyte receptor complex was compared from two haplotypes, the gene content in the KIR region varied dramatically, with framework loci flanking regions of widely variable gene content. The ILT genes were more stable in number except for ILT6, which was present only in one haplotype. Analysis of Alu repeats and comparison of KIR gene sequences, which are over 90% identical, are consistent with a recent origin. KIR genesis was followed by extensive duplication/deletion as well as intergenic sequence exchange, reminiscent of MHC class I genes, which provide KIR ligands.

Tetrodes markedly improve the reliability and yield of multiple single-unit isolation from multi-unit recordings in cat striate cortex

The majority of techniques for separating multiple single-unit spike trains from a multi-unit recording rely on the assumption that different cells exhibit action potentials having unique amplitudes and waveforms. When this assumption fails, due to the similarity of spike shape among different cells or to the presence of complex spikes with declining intra-burst amplitude, these methods lead to errors in classification. In an effort to avoid these errors, the stereotrode (McNaughton et al., 1983) and later the tetrode (O'Keefe and Reece, 1993; Wilson and McNaughton, 1993) recording techniques were developed. Because the latter technique has been applied primarily to the hippocampus, we sought to evaluate its performance in the neocortex. Multi-unit recordings, using single tetrodes, were made at 28 sites in area 17 of 3 anesthetized cats. Neurons were activated with moving bars and square wave gratings. Single units were separated by identification of clusters in 2-D projections of either peak-to-peak amplitude, spike width, spike area, or the 1st versus 2nd principal components of the waveforms recorded on each channel. Using tetrodes, we recorded a total of 154 single cells (mean = 5.4, max = 9). By cross-checking the performance of the tetrode with the stereotrode and electrode, we found that the best of the 6 possible stereotrode pairs and the best of 4 possible electrodes from each tetrode yielded 102 (mean = 3.6, max = 7) and 95 (mean = 3.4, max = 6) cells, respectively. Moreover, we found that the number of cells isolated at each site by the tetrode was greater than the stereotrode or electrode in 16/28 and 28/28 cases, respectively. Thus, both stereotrodes, and particularly electrodes, often lumped 2 or more cells in a single cluster that could be easily separated by the tetrode. We conclude that tetrode recording currently provides the best and most reliable method for the isolation of multiple single units in the neocortex using a single probe.

Trajectory encoding in the hippocampus and entorhinal cortex

We recorded from single neurons in the hippocampus and entorhinal cortex (EC) of rats to investigate the role of these structures in navigation and memory representation. Our results revealed two novel phenomena: first, many cells in CA1 and the EC fired at significantly different rates when the animal was in the same position depending on where the animal had come from or where it was going. Second, cells in deep layers of the EC, the targets of hippocampal outputs, appeared to represent the similarities between locations on spatially distinct trajectories through the environment. Our findings suggest that the hippocampus represents the animal's position in the context of a trajectory through space and that the EC represents regularities across different trajectories that could allow for generalization across experiences.

Evolutionary social psychology and family homicide

Homicide is an extreme manifestation of interpersonal conflict with minimal reporting bias and can thus be used as a conflict "assay." Evolutionary models of social motives predict that genetic relationship will be associated with mitigation of conflict, and various analyses of homicide data support this prediction. Most "family" homicides are spousal homicides, fueled by male sexual proprietariness. In the case of parent-offspring conflict, an evolutionary model predicts variations in the risk of violence as a function of the ages, sexes, and other characteristics of protagonists, and these predictions are upheld in tests with data on infanticides, parricides, and filicides.

Exploring drug-induced alterations in gene expression in Mycobacterium tuberculosis by microarray hybridization

Tuberculosis is a chronic infectious disease that is transmitted by cough-propelled droplets that carry the etiologic bacterium, Mycobacterium tuberculosis. Although currently available drugs kill most isolates of M. tuberculosis, strains resistant to each of these have emerged, and multiply resistant strains are increasingly widespread. The growing problem of drug resistance combined with a global incidence of seven million new cases per year underscore the urgent need for new antituberculosis therapies. The recent publication of the complete sequence of the M. tuberculosis genome has made possible, for the first time, a comprehensive genomic approach to the biology of this organism and to the drug discovery process. We used a DNA microarray containing 97% of the ORFs predicted from this sequence to monitor changes in M. tuberculosis gene expression in response to the antituberculous drug isoniazid. Here we show that isoniazid induced several genes that encode proteins physiologically relevant to the drug's mode of action, including an operonic cluster of five genes encoding type II fatty acid synthase enzymes and fbpC, which encodes trehalose dimycolyl transferase. Other genes, not apparently within directly affected biosynthetic pathways, also were induced. These genes, efpA, fadE23, fadE24, and ahpC, likely mediate processes that are linked to the toxic consequences of the drug. Insights gained from this approach may define new drug targets and suggest new methods for identifying compounds that inhibit those targets.

Toxoplasma gondii infection in the United States: seroprevalence and risk factors

Infection with Toxoplasma gondii can cause severe illness when the organism is contracted congenitally or when it is reactivated in immune-suppressed persons. To determine the prevalence of T. gondii infection in a representative sample of the US population, the authors tested sera from participants in the Third National Health and Nutrition Examination Survey (1988-1994) for immunoglobulin G antibodies to T. gondii. Of 27,145 persons aged > or =12 years, 17,658 (65%) had sera tested. The overall age-adjusted seroprevalence was 22.5% (95% confidence interval (CI): 21.1, 23.9); among women aged 15-44 years, seroprevalence was 15.0% (95% CI: 13.2, 17.0). Age-adjusted seroprevalence was higher in the Northeast (29.2%) than in the South (22.8%), Midwest (20.5%), or West (17.5%) (p < 0.05). In multivariate analysis, risk for T. gondii infection increased with age and was higher among persons who were foreign-born, persons with a lower educational level, those who lived in crowded conditions, and those who worked in soil-related occupations, although in subset analyses risk categories varied by race/ethnicity. Nearly one quarter of adults and adolescents in the United States have been infected with T. gondii. Most women of childbearing age in the United States are susceptible to acute infection and should be educated about ways to minimize exposure to T. gondii.

Bacterially induced bone destruction: mechanisms and misconceptions

Normal bone remodelling requires the coordinated regulation of the genesis and activity of osteoblast and osteoclast lineages. Any interference with these integrated cellular systems can result in dysregulation of remodelling with the consequent loss of bone matrix. Bacteria are important causes of bone pathology in common conditions such as periodontitis, dental cysts, bacterial arthritis, and osteomyelitis. It is now established that many of the bacteria implicated in bone diseases contain or produce molecules with potent effects on bone cells. Some of these molecules, such as components of the gram-positive cell walls (lipoteichoic acids), are weak stimulators of bone resorption in vitro, while others (PMT, cpn60) are as active as the most active mammalian osteolytic factors such as cytokines like IL-1 and TNF. The complexity of the integration of bone cell lineage development means that there are still question marks over the mechanism of action of many well-known bone-modulatory molecules such as parathyroid hormone. The key questions which must be asked of the now-recognized bacterial bone-modulatory molecules are as follows: (i) what cell population do they bind to, (ii) what is the nature of the receptor and postreceptor events, and (iii) is their action direct or dependent on the induction of secondary extracellular bone-modulating factors such as cytokines, eicosanoids, etc. In the case of LPS, this ubiquitous gram-negative polymer probably binds to osteoblasts or other cells in bone through the CD14 receptor and stimulates them to release cytokines and eicosanoids which then induce the recruitment and activation of osteoclasts. This explains the inhibitor effects of nonsteroidal and anticytokine agents on LPS-induced bone resorption. However, other bacterial factors such as the potent toxin PMT may act by blocking the normal maturation pathway of the osteoblast lineage, thus inducing dysregulation in the tightly regulated process of resorption and replacement of bone matrix. At the present time, it is not possible to define a general mechanism by which bacteria promote loss of bone matrix. Many bacteria are capable of stimulating bone matrix loss, and the information available would suggest that each organism possesses different factors which interact with bone in different ways. With the rapid increase in antibiotic resistance, particularly with Staphylococcus aureus and M. tuberculosis, organisms responsible for much bone pathology in developed countries only two generations ago, we would urge that much greater attention should be focused on the problem of bacterially induced bone remodelling in order to define pathogenetic mechanisms which could be therapeutic targets for the development of new treatment modalities.

DSM-III and the transformation of American psychiatry: a history

The author traces the history of the development of DSM-III within the larger context--intellectual, economic, scientific, and ideological--of the development of American psychiatry since World War II. Data were obtained through a literature review, investigation of archival material from the DSM-III task force and APA, and interviews with key participants. This research indicates that from the end of World War II until the mid-1970s, a broadly conceived biopsychosocial model, informed by psychoanalysis, sociological thinking, and biological knowledge, was the organizing model for American psychiatry. However, the biopsychosocial model did not clearly demarcate the mentally well from the mentally ill, and this failure led to a crisis in the legitimacy of psychiatry by the 1970s. The publication of DSM-III in 1980 represented an answer to this crisis, as the essential focus of psychiatric knowledge shifted from the clinically-based biopsychosocial model to a research-based medical model. The author concludes that while DSM-III, and the return to descriptive psychiatry which it inaugurated, has had positive consequences for the profession, at the same time it represents a significant narrowing of psychiatry's clinical gaze.

Improved gas chromatographic method for the determination of nicotine and cotinine in biologic fluids

Improved methods have been developed for the determination of nicotine and its major metabolite, cotinine, in blood, plasma, and urine samples. These methods utilize gas chromatography with alkali flame ionization (nitrogen--phosphorus) detection and structural analogs of nicotine and cotinine as internal standards.

Life expectancy, economic inequality, homicide, and reproductive timing in Chicago neighbourhoods

In comparisons among Chicago neighbourhoods, homicide rates in 1988-93 varied more than 100-fold, while male life expectancy at birth ranged from 54 to 77 years, even with effects of homicide mortality removed. This "cause deleted" life expectancy was highly correlated with homicide rates; a measure of economic inequality added significant additional prediction, whereas median household income did not. Deaths from internal causes (diseases) show similar age patterns, despite different absolute levels, in the best and worst neighbourhoods, whereas deaths from external causes (homicide, accident, suicide) do not. As life expectancy declines across neighbourhoods, women reproduce earlier; by age 30, however, neighbourhood no longer affects age specific fertility. These results support the hypothesis that life expectancy itself may be a psychologically salient determinant of risk taking and the timing of life transitions.

Neurocysticercosis in an Orthodox Jewish community in New York City

BACKGROUND AND METHODS

From June 1990 through July 1991, intracerebral infection with the larval stage of the pork tapeworm Taenia solium was diagnosed in four unrelated persons in an Orthodox Jewish community in New York City. None of the patients had eaten pork, and only one had traveled to a country in which T. solium infection was endemic. We investigated this outbreak, screened serum samples from family members and household contacts for antibodies to cysticercosis, and examined stool specimens from household employees for eggs of taenia species.

RESULTS

The four patients had recurrent seizures and brain lesions that were radiologically consistent with the presence of cysticerci. The diagnosis was confirmed in two patients by a brain biopsy, and in two by immunoblot assays for cysticercus antibodies. Of 17 immediate family members screened serologically, 7 from two families had cysticercus antibodies. Magnetic resonance imaging of the brain showed cystic lesions in two of the seropositive family members, one of whom had had a seizure. Examinations of six domestic employees from all four households revealed an active infection with taenia species in one and a positive serologic test in another. Since these women had recently emigrated from Latin American countries where T. solium infection is endemic, they were the most likely sources of infection in the members of these households.

CONCLUSIONS

A diagnosis of neurocysticercosis should be considered in patients with seizures and radiologic evidence of cystic brain lesions, even in those who do not eat pork and who have not traveled to a country in which T. solium infection is endemic. Recent emigrants from countries in which T. solium infection is endemic should be screened for tapeworm infection in their stools before they are employed as housekeepers or food handlers.

Effects of creatine supplementation on body composition, strength, and sprint performance

PURPOSE

To determine the effects of 28 d of creatine supplementation during training on body composition, strength, sprint performance, and hematological profiles.

METHODS

In a double-blind and randomized manner, 25 NCAA division IA football players were matched-paired and assigned to supplement their diet for 28 d during resistance/agility training (8 h x wk[-1]) with a Phosphagen HP (Experimental and Applied Sciences, Golden, CO) placebo (P) containing 99 g x d(-1) of glucose, 3 g x d(-1) of taurine, 1.1 g x d(-1) of disodium phosphate, and 1.2 g x d(-1) of potassium phosphate (P) or Phosphagen HP containing the P with 15.75 g x d(-1) of HPCE pure creatine monohydrate (HP). Before and after supplementation, fasting blood samples were obtained; total body weight, total body water, and body composition were determined; subjects performed a maximal repetition test on the isotonic bench press, squat, and power clean; and subjects performed a cycle ergometer sprint test (12 x 6-s sprints with 30-s rest recovery).

RESULTS

Hematological parameters remained within normal clinical limits for active individuals with no side effects reported. Total body weight significantly increased (P < 0.05) in the HP group (P 0.85 +/- 2.2; HP 2.42 +/- 1.4 kg) while no differences were observed in the percentage of total body water. DEXA scanned body mass (P 0.77 +/- 1.8; HP 2.22 +/- 1.5 kg) and fat/bone-free mass (P 1.33 +/- 1.1; HP 2.43 +/- 1.4 kg) were significantly increased in the HP group. Gains in bench press lifting volume (P -5 +/- 134; HP 225 +/- 246 kg), the sum of bench press, squat, and power clean lifting volume (P 1,105 +/- 429; HP 1,558 +/- 645 kg), and total work performed during the first five 6-s sprints was significantly greater in the HP group.

CONCLUSION

The addition of creatine to the glucose/taurine/electrolyte supplement promoted greater gains in fat/bone-free mass, isotonic lifting volume, and sprint performance during intense resistance/agility training.

The genomic context of natural killer receptor extended gene families

The two sets of inhibitory and activating natural killer (NK) receptor genes belong either to the Ig or to the C-type lectin superfamilies. Both are extensive and diverse, comprising genes of varying degrees of relatedness, indicative of a process of iterative duplication. We have constructed gene maps to help understand how and when NK receptor genes developed and the nature of their polymorphism. A cluster of over 15 C-type lectin genes, the natural killer complex is located on human chromosome 12p13.1, syntenic with a region in mouse that borders multiple Ly49 loci. The equivalent locus in man is occupied by a single pseudogene, LY49L. The immunoglobulin superfamily of loci, the leukocyte receptor complex (LRC), on chromosome 19q13.4, contains many polymorphic killer cell immunoglobulin-like receptor (KIR) genes as well as multiple related sequences. These include immunoglobulin-like transcript (ILT) (or leukocyte immunoglobulin-like receptor genes), leukocyte-associated inhibitory receptor genes (LAIR), NKp46, Fc alphaR and the platelet glycoprotein receptor VI locus, which encodes a collagen-binding molecule. KIRs are expressed mostly on NK cells and some T cells. The other LRC loci are more widely expressed. Further centromeric of the LRC are sets of additional loci with weak sequence similarity to the KIRs, including the extensive CD66(CEA) and Siglec families. The LRC-syntenic region in mice contains no orthologues of KIRs. Some of the KIR genes are highly polymorphic in terms of sequence as well as for presence/absence of genes on different haplotypes. Some anchor loci, such as KIR2DL4, are present on most haplotypes. A few ILT loci, such as ILT5 and ILT8, are polymorphic, but only ILT6 exhibits presence/absence variation. This knowledge of the genomic organisation of the extensive NK superfamilies underpins efforts to understand the functions of the encoded NK receptor molecules. It leads to the conclusion that the functional homology of human KIR and mouse Ly49 genes arose by convergent evolution. NK receptor immunogenetics has interesting parallels with the major histocompatibility complex (MHC) in which some of the polymorphic genes are ligands for NK molecules. There are hints of an ancient genetic relationship between NK receptor genes and MHC-paralogous regions on chromosomes 1, 9 and 19. The picture that emerges from both complexes is of eternal evolutionary restlessness, presumably in response to resistance to disease.

A novel chimeric Ig heavy chain from a teleost fish shares similarities to IgD

IgD is considered to be a recently evolved Ig, being previously found only in primates and rodents. Here we describe, from a teleost fish (the channel catfish, Ictalurus punctatus), a novel complex chimeric Ig heavy chain, homologous, in part, to the heavy chain (delta) of IgD. In addition to alternative secretory or membrane-associated C termini, this chimeric molecule contains a rearranged variable domain, the first constant domain of mu, and seven constant domains encoded by a delta gene homolog. Identification of the catfish gene as delta is based on the following properties: sequence relatedness to mammalian delta; a location within the IgH locus that is immediately downstream of the mu gene; separate terminal exons for the secretory and membrane forms; coexpression with the complete mu chain in some but not all B cells. These results (i) suggest that IgD is an ancient immunoglobulin that was present in vertebrates ancestral to both the mammals and the ray-finned fishes, and (ii) raise the possibility that this Ig isotype may have served an as yet unidentified important function early in the evolution of the immune system.

A review of the microbiology, antibiotic usage and resistance in chronic skin wounds

Chronic leg and foot wounds represent an increasing burden to healthcare systems as the age of the population increases. The deep dermal tissues of all chronic wounds harbour microorganisms, however, the precise interaction between microbes in the wounds and impaired healing is unknown. With regard to antibiotic therapy, there is a lack of evidence concerning its effectiveness, optimal regimens or clinical indications for treatment. Despite this lack of evidence, antibiotics are frequently a feature of the management of chronic wounds and these patients receive significantly more antibiotic prescriptions (both systemic and topical) than age and sex-matched patients. Current guidelines for antibiotic prescribing for such wounds are often based on expert opinion rather than scientific fact and may present difficulties in interpretation and implementation to the clinician. Although the increasing prevalence of antibiotic resistance is widely recognized, the relationships between antibiotic resistance, chronic wound microbiology and rationales for antibiotic therapy have yet to be determined. This review discusses the role of microbes in chronic wounds from a clinical perspective with particular focus on the occurrence of bacteria and their impact on such wounds. The evidence and role of antibiotics in the treatment of such wounds are outlined and current practice of antibiotic usage for chronic wounds in the primary care setting described. The implications of antibiotic usage with regard to antibiotic resistance are also considered.

Lymphocyte heterogeneity in the trout, Salmo gairdneri, defined with monoclonal antibodies to IgM

A monoclonal antibody to trout serum IgM was tested by immunofluorescence analysis with lymphocytes from thymus, spleen and head kidney. By visual examination, the antibody reacted with only a subpopulation of lymphocytes. The mean values +/- SE for positive cells were 5.2 +/- 2.3% in the thymus, 30.3 +/- 7.9% in the spleen and 12.4 +/- 3.0% in the head kidney. Flow cytofluorometric analysis revealed evidence of heterogeneity by size among the membrane IgM-positive cells of the head kidney and spleen. Depletion of head kidney cells positive for surface IgM by an immune affinity adherence technique of panning, using monoclonal anti-IgM, significantly reduced the mitogenic response to lipopolysaccharide but not to concanavalin A. It is suggested that this information supports the existence of distinct subpopulations of fish lymphocytes that may be homologous in certain respects to mammalian T and B type cells.

Hypertension treated by salt restriction

31 patients with a diastolic blood-pressure between 95 and 109 mm Hg have been treated for two years with a regimen involving a moderate restriction of salt in the diet. The results are compared with those in a control group and in a drug-treated group. Salt restriction has reduced the diastolic blood-pressure by 7.3+/-1.6 mm Hg, a result similar to that in patients treated with antihypertensive drugs. In the untreated group the diastolic blood-pressure rose by 1.8+/-1.1 mm Hg. Most patients did not achieve the desired amount of salt restriction and a stricter adherence to the diet might have caused further falls in blood-pressure. Excessive salt intake is probably a major cause of the epidemic of hypertension in "civilised" countries and a reduction in salt intake may help to control the epidemic. In persons with a diastolic blood-pressure between 90 and 105 mm Hg salt restriction should be tried before drugs.

In vivo killing of Porphyromonas gingivalis by toluidine blue-mediated photosensitization in an animal model

Porphyromonas gingivalis is one of the major causative organisms of periodontitis and has been shown to be susceptible to toluidine blue-mediated photosensitization in vitro. The aims of the present study were to determine whether this technique could be used to kill the organism in the oral cavities of rats and whether this would result in a reduction in the alveolar bone loss characteristic of periodontitis. The maxillary molars of rats were inoculated with P. gingivalis and exposed to up to 48 J of 630-nm laser light in the presence of toluidine blue. The number of surviving bacteria was then determined, and the periodontal structures were examined for evidence of any damage. When toluidine blue was used together with laser light there was a significant reduction in the number of viable P. gingivalis organisms. No viable bacteria could be detected when 1 mg of toluidine blue per ml was used in conjunction with all light doses used. On histological examination, no adverse effect of photosensitization on the adjacent tissues was observed. In a further group of animals, after time was allowed for the disease to develop in controls, the rats were killed and the level of maxillary molar alveolar bone was assessed. The bone loss in the animals treated with light and toluidine blue was found to be significantly less than that in the control groups. The results of this study show that toluidine blue-mediated lethal photosensitization of P. gingivalis is possible in vivo and that this results in decreased bone loss. These findings suggest that photodynamic therapy may be useful as an alternative approach for the antimicrobial treatment of periodontitis.

Evaluation of breast cancer risk assessment packages in the family history evaluation and screening programme

INTRODUCTION

Accurate individualised breast cancer risk assessment is essential to provide risk-benefit analysis prior to initiating interventions designed to lower breast cancer risk. Several mathematical models for the estimation of individual breast cancer risk have been proposed. However, no single model integrates family history, hormonal factors, and benign breast disease in a comprehensive fashion. A new model by Tyrer and Cuzick has addressed these deficiencies. Therefore, this study has assessed the goodness of fit and discriminatory value of the Tyrer-Cuzick model against established models namely Gail, Claus, and Ford.

METHODS

The goodness of fit and discriminatory accuracy of the models was assessed using data from 1933 women attending the Family History Evaluation and Screening Programme, of whom 52 developed cancer. All models were applied to these women over a mean follow up of 5.27 years to estimate risk of breast cancer.

RESULTS

The ratios (95% confidence intervals) of expected to observed numbers of breast cancers were 0.48 (0.37 to 0.64) for Gail, 0.56 (0.43 to 0.75) for Claus, 0.49 (0.37 to 0.65) for Ford, and 0.81 (0.62 to 1.08) for Tyrer-Cuzick. The accuracy of the models for individual cases was evaluated using ROC curves. These showed that the area under the curve was 0.735 for Gail, 0.716 for Claus, 0.737 for Ford, and 0.762 for Tyrer-Cuzick.

CONCLUSION

The Tyrer-Cuzick model is the most consistently accurate model for prediction of breast cancer. The Gail, Claus, and Ford models all significantly underestimate risk, although the accuracy of the Claus model may be improved by adjustments for other risk factors.

Susceptibility of oral bacterial biofilms to antimicrobial agents

There is great interest in the use of antimicrobial agents for the prevention and treatment of plaque-related oral diseases and many publications have reported the results of studies in which the minimum inhibitory concentrations of agents for cariogenic and periodontopathogenic bacteria have been determined. However, such data are relevant only to situations where the organisms of interest are in aqueous suspension, whereas in caries and the inflammatory periodontal diseases the target organisms are in the form of biofilms. On the basis of studies with medically important bacteria, it has been established that bacteria in biofilms are invariably less susceptible to antimicrobial agents than their planktonic counterparts. Therefore, in the laboratory assessment of agents which may be suitable for treating plaque-related diseases, the target organisms should be in the form of biofilms. While laboratory evaluation of chemical agents for the prevention of plaque formation has usually employed biofilm-based models, the search for antimicrobial agents effective in the treatment of plaque-related diseases has not. Therefore, there are few data available regarding those characteristics of antimicrobial agents (e.g., their biofilm eliminating concentrations or biofilm killing concentrations) that could be used to judge their suitability for treating plaque-related diseases. In this review the limited information available concerning the antimicrobial susceptibility of oral bacteria in biofilms is presented.

Clinical evaluation of the cysticercosis enzyme-linked immunoelectrotransfer blot in patients with neurocysticercosis

During the 3 years that the enzyme-linked immunoelectrotransfer blot (EITB) assay for the diagnosis of human cysticercosis has been in use at the Centers for Disease Control, 50 patients with both pathologically confirmed neurocysticercosis and computed tomographic (CT) or magnetic resonance imaging (MRI) scan results were identified. Of 32 patients with two or more lesions, 94% had detectable antibodies by EITB compared with 28% of 18 patients with single lesions. Patients with only calcified cysts (single or multiple) were less likely to have EITB-positive results than were those with noncalcified, enhancing lesions. Antibody was detectable more frequently in serum than in cerebrospinal fluid, regardless of the number or apparent condition of the cysts. These findings confirm that the EITB assay for cysticercosis antibodies is highly sensitive in patients with multiple, enhancing intracranial lesions but is less sensitive in patients with single lesions and in those with calcified lesions.